# User:Abc1357/LG

## Lanes

Details on Lanes and how to map them can be found on the Lanes Wazeopedia page. Editors should consider using the Lane Tools script to assist in mapping lanes correctly.

In California, Lanes should be mapped for major intersections where the number of turn lanes deviates from what is expected. In other words, do not map if you can turn right only from the right lane and/or you can turn left only from the left lane, regardless of whether these lanes are dedicated turn lanes or shared lanes.

Intersections where you should map Lanes*:

• In a # or H junction where there is a U-Turn, even if there is only a single left turn lane.  The addition of Lanes to these intersections combined with lane heuristics enables Waze to announce a `U-Turn`, rather than a `Turn Left, Turn Left`.
• Verify that the parallel segments are almost parallel (i.e. sum of angles with the cross segment should be between 175° and 185°), and the angle with the cross segment should be close to 90°.
• Check that there is not a parallel segment within 50m (165 ft) to the left of the segment with a single perpendicular segment connecting them. Waze heuristics could interpret that to be U-Turn. Use a Junction Node to "break up" the median segment. Put in a picture of Clarie Drive in Pleasant Hill https://www.waze.com/en-US/editor/?env=usa&lon=-122.05663&lat=37.94113&zoom=8&segments=522544024,522544023
• Use the `View and Hear` or `View Only` continue straight overrides where necessary

* Before mapping Lanes at any intersection, review prior intersections to ensure adding Lanes at that intersection do not inadvertently cause confusion for the driver (see Compound Guidance needed section below).

### Special Considerations

When reviewing intersections prior to adding Lanes, please consider whether AGCs are still needed at that intersection.

For example, the AGC from westbound Walsh Avenue to northbound San Tomas Expressway is not needed. The island is extremely small. The benefits that the AGC was originally meant for, such as advanced announcement of the turn, are not needed.

What should be done in this situation?

• Remove the AGC and excess Junction Nodes
• Check to ensure Turn Restrictions are correct for the intersection

#### Compound Guidance needed

Compound guidance is the concept where a driver should be directed to a specific lane or set of lanes at a prior intersection to ensure that the driver is in position to perform the turn maneuver. Unfortunately, Waze does not yet support compound guidance.

Lane specific guidance

There are intersections where users should be guided to the proper lane in preparation for the next maneuver.

Consider a driver going from Crow Canyon Place to I-680 North. There are 2 left turn lanes on Crow Canyon Place. An editor following lane mapping guidance would map that intersection with 2 left turns. A driver unfamiliar with that area could potentially be using the left lane of the 2 left turn lanes to turn into the left lanes on Crow Canyon Road and not be able to enter the on-ramp to I-680 North, if there is a lot of traffic blocking the movement to the right lanes in the short distance available.

In order to properly guide the driver, some sort of compound guidance such as `Use the right of the two left turn lanes to turn left and then turn right to I-680 North Sacramento` would be ideal.

Loss and re-gain of lane between 2 intersections

There are intersections where a lane is lost to a dedicated turn lane, and yet, by the next intersection, a lane is re-added. A driver following the lane guidance could mistakenly enter the dedicated turn lane prematurely and may be forced to take the earlier turn.

Consider a driver on Mission Boulevard being guided to northbound I-680. There are 3 full lanes at the on-ramp to northbound I-680 with the right lane dedicated to the freeway entrance.

At the prior on-ramp to southbound I-680, there are also 3 full lanes at the on-ramp with the right lane dedicated to the freeway entrance.

Note that since Lane Guidance is announced about ½ mile for MH (and ¼ mile for mH and lower) prior to the turn instruction, the driver would have heard `In ½ mile, use the right lane to turn right to I-680 North Sacramento` at around Warm Springs Boulevard, which is 2 signaled intersections prior to the entrance to northbound I-680. There is no signage that the right lane ends until you are almost at the entrance to southbound I-680. A driver unfamiliar with the area, upon seeing or hearing the guidance, would get into the right lane. By the time the driver realizes that the lane is a dedicated lane to I-680 South, not North, there isn't much distance left to change lanes, especially when there is a lot of traffic in the next lane.
In order to properly guide the driver, there are a few possibilities. Waze could delay announcing the Turn instruction to northbound I-680 until the driver is past the entrance to southbound I-680. A more ideal solution would be for Waze to announce `In ½ mile, stay in the middle lane and then turn right to I-680 North Sacramento`.